Printing-press.



R. T. JOHNSTON.

PRINTING PRESS. APPLICATION FILED DEC. 18, 1911.

Patented Aug. 5, 1913. 2 SHEETS-SHEET 1.

R. T. JOHNSTON.

PRINTING PRESS.

Patented Aug. 5, 1913.

2 SHEETS-SHEET 2.

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APPLICATION FILED DEC. 18, 1911. 1 ,140.

ROBERT TAYLOR JOHNSTON, 0F SCOTCH PLAINS, NEW JERSEY.

PRINTING-PRESS.

Specification of Letters Patent.

Application filed December 18, 1911.

Patented Aug. 5,1913.

Serial No. 666,355.

To all whom it may concern:

Be it known that I, ROBERT TAYLOR J OHNS- TON, a citizen of the United States, residing at Scotch Plains, in the county of Union and State of New Jersey, have invented certain new and useful, Improvements in Printing-Presses, of which the following is a specification.

This invention pertains to printing presses and more particularly to improved inking mechanism and means for operating the same especially applicable to presses of the bed and cylinder type.

In my co-pending application, Serial No. 666,354 filed concurrently herewith, I have disclosed an arrangement and method of mounting the inking rolls and also cam mechanism mounted on the printing bed for raising and lowering the rolls at predetermined positions of the bed.

My present invention relates to novel mechanism for raising and lowering the inking rolls when mounted substantially in the manner disclosed in said co-pending application and to novel adjusting mechanism whereby the timing of the raising and lowering operations may be regulated to correspond to the variations in position of the central margin of the printing form.

One preferred embodiment of my invention and its method of operation will be readily understood from the following description when considered in connection with the accompanying drawings throughout the various views of which like reference characters refer to similar parts.

Referring to the drawingsFigure 1 is a fragmentary side elevation of a printing press embodying one form of my invention. Fig. 2 is a plan view of one side of the machine, certaln parts being removed to more clearly show those lying underneath. Fig. 3 is an end elevation of one side of the ma chine looking toward the left in Figs. 1 and 2; and Fig. 4 is an enlarged view of the adjustable cam employed.

Upon the main frame 5 of the machine is rotatably mounted the impression cylinder 6 equipped with the gear wheel 7 which is driven from the driving gear 8 on the driving shaft 9 through the intermediary of the idler 11. The reciprocatory bed 12 is mounted on the frame 5 in the usual manner, reciprocatory motion being imparted thereto by any well known or preferred mechanism (not shown) connected with the inner end of the driving shaft 9.. The usual printing form is carried by the bed 12 to cotiperate, upon reciprocation of the bed, with the impression cylinder 6 and this form, in accordance with the requirements of the work done on machines of this character, is divided by a central margin 13 into a head portion 14 and a tail portion 15. These head and tail portions of the form may be of any preferred construction although customarily they are made up of a number of individual sections each provided with suitable printing characters or surfaces.

The inking rolls are all mounted at one side of the impression cylinder but in order to ink the individual portions of the printing form separately and independently the rolls are divided into sets. the set 16 nearest the cylinder, hereinafter referred to as the head mechanism, being designed to ink the head portion 14 of the form and the set 17 more remote from the cylinder, and hereinafter referred to as the tail mechanism, being adapted to ink the tail portion 15 of the form. The individual inking rolls of each set are mounted upon reciprocatory plates 18 retained in operative position upon the main frame by suitable guides and adapted to be reciprocated to raise and lower the rolls by the cam members 19 provided with the cam slots 21 and 22 in which the cam followers 23 carried by the arms 24 fixed on the shafts 25 are adapted to travel, the oscillatory movements imparted thereby to said shafts 25 being transmitted to the plates 18 through rack and gear connections whereby to raise and lower the inking rolls in succession, all as described more in detail in my co-pending application hereinbefore mentioned.

The cam members .19 in the present instance instead of being mounted directly on the reciprocatory bed are mounted on the sides of the machine frame and reciprocated by suitable mechanism to raise and lower the inking rolls at the proper time, said the shaft 25 at the proper times from a cam 29 mountedon the cam shaft30 and provided with a track 31 in which travels a follower 32 mounted on the lever 33 pivoted to the main frame at 3s and connected at its upper end with arack bar 35 meshing with a gear 36 fixed on the shaft 28. Rotary movement of the shaft 30 is accordingly transmitted through the intermediary of the rack and gear connection to the cam members 19. the movement of the rack bar 35 being multiplied by reason of the differences in the size of the gears 36 and 27 so that the cam members are rcciprocated at a linear speed practically equal to the linear Speed of the bed. The shaft 30 is rotated by a gear 2-3? mounted thereon from a gear 38 fixed to a gear 39 meshing with a pinion n on the driving shaft 9. The various gears of the train are preferably so proportioned that the shaft '30 makes one complete revolution :1 t each complete cycle of the bed.

Assuming that the various elements are in the position shown in Fig. 1: The bed 12 is traveling toward the right, the cam 29 is rotating in a clockwise direction the inking rolls of the head mechanism 16 are in elevated position while the rolls of the tail mechanism 17 are in lowered or operative relation to the tail portion 15 of the print ing form. Byreason of the fact that the cam follower has been traveling in the low dwell portion of the cam track 31 the cam members 19 have remained stationary while the actual printing operation was taking place. Upon return movement of the bed, however, it is desirable to bring the inking rolls of the head mechanism succes sively into engagement with the head portion 1 1- of the form and the cam members 19 must therefore, be moved to bring the riser portions of the cam slots successively into operative relation with the cam followers 23.

hen, the central margin 13 reaches aposition under the first inking roll of the head mechanism. the cam 19 will have been moved by engagement of the riser portion of the cam 29 with the follower 32 so that said first roll will be lowered. As the cam 29 continues to rotate the other roll of the head mechanism will be lowered and both rolls of the tail mechanism will be successively raised at the margin 13 while the follower 32 is traveling from low to high position on the cam 29. The follower 32 then travels along the high dwell portion of the cam 29 while the bed is being reversed and upon forward movement of the bed a reverse movement of each of the inking rolls of both sets of mechanisms is effected by return movement of the cam members 19 as the follower 82 travels from the high dwell portion to the low dwell portion of the cam 29. Thus it will be seen that each of the individual inking rolls is successively raised and lowered as the central margin of the printing form passes thereunder.

Since the position of the head line of all ferns employed remains fixed relatively to a predetermined point on the periphery of the printing cylinder, it will be manifest that the position. of the central margin 13 will. necessarily vary in forms of different sizes. In order that the operations of the cam members 19 may be regulated in conformity with the various positions of the central. margin on the printing form to properly time the raising and lowering movements of the individual inking rolls, I have so constructed the cam 29 that it can be adjusted symmetrically on each side of a median line to vary the contour and the lengtlnof the dwell portions of the cam without disturbing its symmetry. The cam, as shown in Fig. 4, consists of two sections 412 and 413 provided with lugs or ears at and 45 having elongated slots 46 and 47, respectively, through which the bolts 48 and 49 are passed to lock the sections to the main or plate portion 51. The section 4L2 is provided with an inwardly projecting rack segment 52 and the section 43 is provided with a similar segment 53, a pinion 54: being mounted between said segments and in mesh therewith so that by rotation of the pinion the sections can be adjusted angularly about the'shaft 30 toward and from each other. The high and low dwell portions of the cam are thereby lengthened and shortened'and the length of the cam track 31 is accordingly increased or diminished without disturbing the symmetry of the cam. After the required adjustment has been made the sections are locked in adjusted position by tighteningup the locking bolts 48 and 19. It will be manifest that by the employment of a cam of this character capable of symmetrical adjustment with respect to a median line the timing of the cam members 19 may be regulated and varied in accordance ith the central margin 13, so that the raising and lowering movements of the inking rolls will always be effected at said margin thereby insuring a uniform inking of each portion of the printing form throughout its entire length without permitting the inking rolls of one inking mechanism to contact with the other portion of the form.

It is believed that my invention and many of its attendant advantages will be understood from the foregoing without further description and, it will be obvious to those skilled in the art, that mechanical elements differing in construction from those disclosed and described may be employed without departing from the spirit of the invention or sacrificing any of the material advantages thereof.

I claim: 7

1. In a printing press, the combination of a reciprocatory bed, a plurality of inking rolls, cam devices mounted to reciprocate longitudinally of the bed for raising and lowering said rolls, and means for reciprocating said devices synchronously with the bed but at variable speeds relatively to the travel of the bed.

2. In a printing press, the combination of a reciprocatory bed, a plurality of inking rolls, reciprocatory cam devices for positively raising and lowering each of said rolls at each reciprocation of the devices, and common driving mechanism including a rotary shaft operatively connected with each of said devices for reciprocating the same synchronously with the bed but through a shorter cycle than the cycle of the bed.

3. 'In a printing press, the combination of a plurality of sets of inking mechanisms each comprising a plurality of individual inking rolls, reciprocatory cam devices for raising and lowering each of said rolls at each complete reciprocation of the devices,

a cross-shaft, rack and gear connections between each of said cam devices and the shaft, and means for rotating said shaft alternately in opposite directions at variable speeds.

4. In a printing press, the combination of a reciprocatory bed, a plurality of inking rolls, a pair of cam devices mounted to reciprocate relatively to the bed and adapted to raise and lower all of the rolls at each reciprocation of said devices, and mechanism including a rotary shaft and a cam mounted thereon for reciprocating said cam devices at variable speeds.

5. In a printing press, the combination of inking rolls, reciprocatory cam devices for raising and lowering said rolls, a shaft, an expansible cam mounted thereon, oper ative connections between said cam and said reciprocatory cam devices, and means for rotating said shaft whereby to raise and lower said rolls through the intermediary of said cam devices.

6. In a printing press, the combination of inking rolls, reciprocatory cam devices,

connections between said devices and said rolls whereby the rolls are raised and lowered at each reciprocation of the devices, and driving mechanism including a rotary shaft and an expansible cam whereby said devices are reciprocated.

7. In a printing press, the combination of an inking roll, a cam device, means for raising and lowering said roll at each cycle of the device, a rotating cam, operative connections-between said cam and the cam device, and means for adjusting the length of the dwell portion of said cam whereby to vary the cycle of said cam device.

8. In a printing press, the combination of an inking roll, a pair of cam devices, means whereby said roll is raised and lowered during each cycle of said devices, a cross-shaft, rack and gear connections between each of said cam devices and said cross-shaft, a rotating cam, operative con nections between said cam and said crossshaft whereby the cross-shaft is rotated alternately in opposite directions upon each rotation of the cam, and means for varying the length of the dwell portion of said rotating cam whereby to vary the timing of the cycles of said cam devices.

9. In a printing press, the combination of a plurality of sets of inking mechanisms each comprising a plurality of individual inking rolls, a pair of cam devices mounted upon opposite sides of the machine, means whereby the individual rolls of each set of inking mechanisms are raised and lowered upon each reciprocation of said cam devices, a cross-shaft, rack and gear connections between said cross-shaft and said cam devices, a rotating cam, operative connections between said cam and said cross-shaft, and means for varying the length of the dwell portion of said cam whereby to vary the reciprocation of said cam devices.

ROBERT TAYLOR JOHNSTON.

Witnesses:

IRA J. WILSON, M. A. KIDDIE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

